Commit | Line | Data |
---|---|---|
22ac9232 | 1 | /* |
3b937a7d | 2 | * drivers/watchdog/orion_wdt.c |
22ac9232 | 3 | * |
3b937a7d | 4 | * Watchdog driver for Orion/Kirkwood processors |
22ac9232 SB |
5 | * |
6 | * Author: Sylver Bruneau <sylver.bruneau@googlemail.com> | |
7 | * | |
8 | * This file is licensed under the terms of the GNU General Public | |
9 | * License version 2. This program is licensed "as is" without any | |
10 | * warranty of any kind, whether express or implied. | |
11 | */ | |
12 | ||
27c766aa JP |
13 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
14 | ||
22ac9232 SB |
15 | #include <linux/module.h> |
16 | #include <linux/moduleparam.h> | |
17 | #include <linux/types.h> | |
18 | #include <linux/kernel.h> | |
19 | #include <linux/fs.h> | |
20 | #include <linux/miscdevice.h> | |
9e058d4f | 21 | #include <linux/platform_device.h> |
22ac9232 SB |
22 | #include <linux/watchdog.h> |
23 | #include <linux/init.h> | |
24 | #include <linux/uaccess.h> | |
25 | #include <linux/io.h> | |
6d0f0dfd | 26 | #include <linux/spinlock.h> |
4f04be62 | 27 | #include <linux/clk.h> |
fdd8b079 | 28 | #include <mach/bridge-regs.h> |
22ac9232 SB |
29 | |
30 | /* | |
31 | * Watchdog timer block registers. | |
32 | */ | |
a855a7ce | 33 | #define TIMER_CTRL 0x0000 |
22ac9232 | 34 | #define WDT_EN 0x0010 |
a855a7ce | 35 | #define WDT_VAL 0x0024 |
22ac9232 | 36 | |
9e058d4f | 37 | #define WDT_MAX_CYCLE_COUNT 0xffffffff |
22ac9232 SB |
38 | #define WDT_IN_USE 0 |
39 | #define WDT_OK_TO_CLOSE 1 | |
40 | ||
86a1e189 | 41 | static bool nowayout = WATCHDOG_NOWAYOUT; |
9e058d4f TR |
42 | static int heartbeat = -1; /* module parameter (seconds) */ |
43 | static unsigned int wdt_max_duration; /* (seconds) */ | |
4f04be62 | 44 | static struct clk *clk; |
9e058d4f | 45 | static unsigned int wdt_tclk; |
a855a7ce | 46 | static void __iomem *wdt_reg; |
22ac9232 | 47 | static unsigned long wdt_status; |
1334f329 | 48 | static DEFINE_SPINLOCK(wdt_lock); |
22ac9232 | 49 | |
3b937a7d | 50 | static void orion_wdt_ping(void) |
df6707b2 TR |
51 | { |
52 | spin_lock(&wdt_lock); | |
53 | ||
54 | /* Reload watchdog duration */ | |
a855a7ce | 55 | writel(wdt_tclk * heartbeat, wdt_reg + WDT_VAL); |
df6707b2 TR |
56 | |
57 | spin_unlock(&wdt_lock); | |
58 | } | |
59 | ||
3b937a7d | 60 | static void orion_wdt_enable(void) |
22ac9232 SB |
61 | { |
62 | u32 reg; | |
63 | ||
6d0f0dfd WVS |
64 | spin_lock(&wdt_lock); |
65 | ||
22ac9232 | 66 | /* Set watchdog duration */ |
a855a7ce | 67 | writel(wdt_tclk * heartbeat, wdt_reg + WDT_VAL); |
22ac9232 SB |
68 | |
69 | /* Clear watchdog timer interrupt */ | |
70 | reg = readl(BRIDGE_CAUSE); | |
71 | reg &= ~WDT_INT_REQ; | |
72 | writel(reg, BRIDGE_CAUSE); | |
73 | ||
74 | /* Enable watchdog timer */ | |
a855a7ce | 75 | reg = readl(wdt_reg + TIMER_CTRL); |
22ac9232 | 76 | reg |= WDT_EN; |
a855a7ce | 77 | writel(reg, wdt_reg + TIMER_CTRL); |
22ac9232 SB |
78 | |
79 | /* Enable reset on watchdog */ | |
6462c616 TR |
80 | reg = readl(RSTOUTn_MASK); |
81 | reg |= WDT_RESET_OUT_EN; | |
82 | writel(reg, RSTOUTn_MASK); | |
6d0f0dfd WVS |
83 | |
84 | spin_unlock(&wdt_lock); | |
22ac9232 SB |
85 | } |
86 | ||
3b937a7d | 87 | static void orion_wdt_disable(void) |
22ac9232 SB |
88 | { |
89 | u32 reg; | |
90 | ||
6d0f0dfd WVS |
91 | spin_lock(&wdt_lock); |
92 | ||
22ac9232 | 93 | /* Disable reset on watchdog */ |
6462c616 TR |
94 | reg = readl(RSTOUTn_MASK); |
95 | reg &= ~WDT_RESET_OUT_EN; | |
96 | writel(reg, RSTOUTn_MASK); | |
22ac9232 SB |
97 | |
98 | /* Disable watchdog timer */ | |
a855a7ce | 99 | reg = readl(wdt_reg + TIMER_CTRL); |
22ac9232 | 100 | reg &= ~WDT_EN; |
a855a7ce | 101 | writel(reg, wdt_reg + TIMER_CTRL); |
6d0f0dfd WVS |
102 | |
103 | spin_unlock(&wdt_lock); | |
104 | } | |
105 | ||
3b937a7d | 106 | static int orion_wdt_get_timeleft(int *time_left) |
6d0f0dfd WVS |
107 | { |
108 | spin_lock(&wdt_lock); | |
a855a7ce | 109 | *time_left = readl(wdt_reg + WDT_VAL) / wdt_tclk; |
6d0f0dfd WVS |
110 | spin_unlock(&wdt_lock); |
111 | return 0; | |
22ac9232 SB |
112 | } |
113 | ||
3b937a7d | 114 | static int orion_wdt_open(struct inode *inode, struct file *file) |
22ac9232 SB |
115 | { |
116 | if (test_and_set_bit(WDT_IN_USE, &wdt_status)) | |
117 | return -EBUSY; | |
118 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
3b937a7d | 119 | orion_wdt_enable(); |
22ac9232 SB |
120 | return nonseekable_open(inode, file); |
121 | } | |
122 | ||
3b937a7d | 123 | static ssize_t orion_wdt_write(struct file *file, const char *data, |
22ac9232 SB |
124 | size_t len, loff_t *ppos) |
125 | { | |
126 | if (len) { | |
127 | if (!nowayout) { | |
128 | size_t i; | |
129 | ||
130 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
131 | for (i = 0; i != len; i++) { | |
132 | char c; | |
133 | ||
134 | if (get_user(c, data + i)) | |
135 | return -EFAULT; | |
136 | if (c == 'V') | |
137 | set_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
138 | } | |
139 | } | |
3b937a7d | 140 | orion_wdt_ping(); |
22ac9232 SB |
141 | } |
142 | return len; | |
143 | } | |
144 | ||
3b937a7d | 145 | static int orion_wdt_settimeout(int new_time) |
df6707b2 TR |
146 | { |
147 | if ((new_time <= 0) || (new_time > wdt_max_duration)) | |
148 | return -EINVAL; | |
149 | ||
150 | /* Set new watchdog time to be used when | |
3b937a7d | 151 | * orion_wdt_enable() or orion_wdt_ping() is called. */ |
df6707b2 TR |
152 | heartbeat = new_time; |
153 | return 0; | |
154 | } | |
155 | ||
156 | static const struct watchdog_info ident = { | |
22ac9232 SB |
157 | .options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | |
158 | WDIOF_KEEPALIVEPING, | |
3b937a7d | 159 | .identity = "Orion Watchdog", |
22ac9232 SB |
160 | }; |
161 | ||
3b937a7d | 162 | static long orion_wdt_ioctl(struct file *file, unsigned int cmd, |
22ac9232 SB |
163 | unsigned long arg) |
164 | { | |
165 | int ret = -ENOTTY; | |
166 | int time; | |
167 | ||
168 | switch (cmd) { | |
169 | case WDIOC_GETSUPPORT: | |
170 | ret = copy_to_user((struct watchdog_info *)arg, &ident, | |
171 | sizeof(ident)) ? -EFAULT : 0; | |
172 | break; | |
173 | ||
174 | case WDIOC_GETSTATUS: | |
175 | case WDIOC_GETBOOTSTATUS: | |
176 | ret = put_user(0, (int *)arg); | |
177 | break; | |
178 | ||
179 | case WDIOC_KEEPALIVE: | |
3b937a7d | 180 | orion_wdt_ping(); |
22ac9232 SB |
181 | ret = 0; |
182 | break; | |
183 | ||
184 | case WDIOC_SETTIMEOUT: | |
185 | ret = get_user(time, (int *)arg); | |
186 | if (ret) | |
187 | break; | |
188 | ||
3b937a7d | 189 | if (orion_wdt_settimeout(time)) { |
22ac9232 SB |
190 | ret = -EINVAL; |
191 | break; | |
192 | } | |
3b937a7d | 193 | orion_wdt_ping(); |
22ac9232 SB |
194 | /* Fall through */ |
195 | ||
196 | case WDIOC_GETTIMEOUT: | |
197 | ret = put_user(heartbeat, (int *)arg); | |
198 | break; | |
199 | ||
200 | case WDIOC_GETTIMELEFT: | |
3b937a7d | 201 | if (orion_wdt_get_timeleft(&time)) { |
22ac9232 SB |
202 | ret = -EINVAL; |
203 | break; | |
204 | } | |
205 | ret = put_user(time, (int *)arg); | |
206 | break; | |
207 | } | |
208 | return ret; | |
209 | } | |
210 | ||
3b937a7d | 211 | static int orion_wdt_release(struct inode *inode, struct file *file) |
22ac9232 SB |
212 | { |
213 | if (test_bit(WDT_OK_TO_CLOSE, &wdt_status)) | |
3b937a7d | 214 | orion_wdt_disable(); |
22ac9232 | 215 | else |
27c766aa | 216 | pr_crit("Device closed unexpectedly - timer will not stop\n"); |
22ac9232 SB |
217 | clear_bit(WDT_IN_USE, &wdt_status); |
218 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); | |
219 | ||
220 | return 0; | |
221 | } | |
222 | ||
223 | ||
3b937a7d | 224 | static const struct file_operations orion_wdt_fops = { |
22ac9232 SB |
225 | .owner = THIS_MODULE, |
226 | .llseek = no_llseek, | |
3b937a7d NP |
227 | .write = orion_wdt_write, |
228 | .unlocked_ioctl = orion_wdt_ioctl, | |
229 | .open = orion_wdt_open, | |
230 | .release = orion_wdt_release, | |
22ac9232 SB |
231 | }; |
232 | ||
3b937a7d | 233 | static struct miscdevice orion_wdt_miscdev = { |
22ac9232 SB |
234 | .minor = WATCHDOG_MINOR, |
235 | .name = "watchdog", | |
3b937a7d | 236 | .fops = &orion_wdt_fops, |
22ac9232 SB |
237 | }; |
238 | ||
3b937a7d | 239 | static int __devinit orion_wdt_probe(struct platform_device *pdev) |
22ac9232 | 240 | { |
a855a7ce | 241 | struct resource *res; |
22ac9232 SB |
242 | int ret; |
243 | ||
4f04be62 AL |
244 | clk = clk_get(&pdev->dev, NULL); |
245 | if (IS_ERR(clk)) { | |
246 | printk(KERN_ERR "Orion Watchdog missing clock\n"); | |
9e058d4f TR |
247 | return -ENODEV; |
248 | } | |
4f04be62 AL |
249 | clk_prepare_enable(clk); |
250 | wdt_tclk = clk_get_rate(clk); | |
9e058d4f | 251 | |
a855a7ce JC |
252 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
253 | ||
254 | wdt_reg = ioremap(res->start, resource_size(res)); | |
255 | ||
3b937a7d | 256 | if (orion_wdt_miscdev.parent) |
9e058d4f | 257 | return -EBUSY; |
3b937a7d | 258 | orion_wdt_miscdev.parent = &pdev->dev; |
9e058d4f TR |
259 | |
260 | wdt_max_duration = WDT_MAX_CYCLE_COUNT / wdt_tclk; | |
3b937a7d | 261 | if (orion_wdt_settimeout(heartbeat)) |
9e058d4f | 262 | heartbeat = wdt_max_duration; |
6d0f0dfd | 263 | |
3b937a7d | 264 | ret = misc_register(&orion_wdt_miscdev); |
9e058d4f TR |
265 | if (ret) |
266 | return ret; | |
267 | ||
27c766aa JP |
268 | pr_info("Initial timeout %d sec%s\n", |
269 | heartbeat, nowayout ? ", nowayout" : ""); | |
9e058d4f TR |
270 | return 0; |
271 | } | |
272 | ||
3b937a7d | 273 | static int __devexit orion_wdt_remove(struct platform_device *pdev) |
9e058d4f TR |
274 | { |
275 | int ret; | |
276 | ||
277 | if (test_bit(WDT_IN_USE, &wdt_status)) { | |
3b937a7d | 278 | orion_wdt_disable(); |
9e058d4f TR |
279 | clear_bit(WDT_IN_USE, &wdt_status); |
280 | } | |
281 | ||
3b937a7d | 282 | ret = misc_deregister(&orion_wdt_miscdev); |
9e058d4f | 283 | if (!ret) |
3b937a7d | 284 | orion_wdt_miscdev.parent = NULL; |
22ac9232 | 285 | |
4f04be62 AL |
286 | clk_disable_unprepare(clk); |
287 | clk_put(clk); | |
288 | ||
22ac9232 SB |
289 | return ret; |
290 | } | |
291 | ||
3b937a7d | 292 | static void orion_wdt_shutdown(struct platform_device *pdev) |
df6707b2 TR |
293 | { |
294 | if (test_bit(WDT_IN_USE, &wdt_status)) | |
3b937a7d | 295 | orion_wdt_disable(); |
df6707b2 TR |
296 | } |
297 | ||
3b937a7d NP |
298 | static struct platform_driver orion_wdt_driver = { |
299 | .probe = orion_wdt_probe, | |
300 | .remove = __devexit_p(orion_wdt_remove), | |
301 | .shutdown = orion_wdt_shutdown, | |
9e058d4f TR |
302 | .driver = { |
303 | .owner = THIS_MODULE, | |
3b937a7d | 304 | .name = "orion_wdt", |
9e058d4f TR |
305 | }, |
306 | }; | |
307 | ||
b8ec6118 | 308 | module_platform_driver(orion_wdt_driver); |
22ac9232 SB |
309 | |
310 | MODULE_AUTHOR("Sylver Bruneau <sylver.bruneau@googlemail.com>"); | |
3b937a7d | 311 | MODULE_DESCRIPTION("Orion Processor Watchdog"); |
22ac9232 SB |
312 | |
313 | module_param(heartbeat, int, 0); | |
df6707b2 | 314 | MODULE_PARM_DESC(heartbeat, "Initial watchdog heartbeat in seconds"); |
22ac9232 | 315 | |
86a1e189 | 316 | module_param(nowayout, bool, 0); |
df6707b2 TR |
317 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" |
318 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); | |
22ac9232 SB |
319 | |
320 | MODULE_LICENSE("GPL"); | |
321 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |